Curtain ring



FIG. 1 is a perspective view of a curtain ring showing my new design;

FIG. 2 is a front side view thereof;

FIG. 3 is a second side view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a front elevational view thereof. 

The ornamental design for a curtain ring, as shown and described. 